* Provide support to query the active port on PA's default sink
This commit exposes 2 objects:
- pa_sink_active_port_name
(example value: "analog-output-headphones")
- pa_sink_active_port_description
(example value: "Headphones")
that give respectively the name and description strings
for the active port on the default sink provided by PulseAudio.
* Reflect 9ed28f2a in the documentation
* Add native support for pulseaudio.
This adds ability to get Pulseaudio current volume without calling an
external program. Also it provides a few other parameters like card's
current profile similarly to pavucontrol. Currently it only queries the
default sink (and associated card).
* Switch to pulse async API.
This us by far the most efficient as conky subscribe to a few pulseaudio
notifications. Whenever pulseaudio server changes (volume or default
sink or default card), conky's callback updates the results.
